Sheet material



Patented Sept. 10, 1940 SHEET MATERIAL Grace P. Ketter and George Wagner, Milwaukee, Wis.

No Drawing. Application October 8, 1936, Serial No; 104,739

3 Claims.

This invention relates to sheet materials for use primarily as stencils, in the blasting or etching of characters or designs upon glass, marble, and the like, although other varied uses are con- 5 templated.

In the use of stencils for the purposes mentioned, it is essential to provide intimate contact between the stencil and panel to be blasted, in order to obtain a sharp outline for the character or design, and, therefore, it is common practice to employ an adhesive material for securing the stencil to the work. Also, due to the abrasive action of the blasting material, the stencil sheet must have sufiicient wear resisting properties to prevent cutting or mutilation by the blasting material.

To meet the foregoing requirements, various types of stencil sheets have been provided, the main objection to which resides in their extremely high cost, and the difficulty in cutting or otherwise working them, in addition to the fact that they are provided with a normally tacky or sticky surface, which requires the use of a protective covering, such as Holland cloth, wax paper, or the like, during handling and shipping. As a matter of fact, one of the most commonly used stencil sheets now on the market is so expensive that it is customary to return the used, mutilated sheets and cut-out sheets to the factory for reworking into new sheets, which in itself entails additional expense and inconvenience.

One object of the present invention is to overcome the foregoing objections by the provisions of an inexpensive stencil sheet, which can be readily and intimately afiixed to the face of a work piece and as readily removed therefrom, and which normally has a relatively smooth, nontacky surface, rendering it easy to handle and ship, as well as facilitating marking and cutting to form the stencil.

Incidental to the foregoing, a more specific object resides in the provision of a stencil sheet of uncalendered and unsized paper of highly absorptive quality, both saturated and covered with 45 an adhesive material normally non-tacky but soluble in water for attachment or removal from the work, and providing a normally smooth surface characterized by its wear resisting qualities.

Other objects and advantages will appear, expressed or implied, from the following description of an illustrative embodiment of the present invention.

The material of the present invention comprises, as a base, a sheet of absorbent material, preferably uncalendered and unsized paper, im-

pregnated and covered preferably on both sides with an adhesive material capable of imparting to the finished sheet the properties, above described, although for some purposes other absorbent sheet material, such as Cellophane may be used as a base. The adhesive material, being absorbed by the sheet, serves as an effective binder to hold the fibres of the sheet together, thus increasing the tensile strength of the finished sheet and making possible the use of relatively thin material without danger of tearing in handling or shipping.

The adhesive material may be applied to the sheet in any conventional manner, such as by dipping or coating, it being understood that by any method employed, sufiicient adhesive material is preferably applied to the sheet materials to saturate the same and to provide a complete covering of the surface fibres, whereas in certain types of stencil sheets it is the practice to pass the material through rollers after the same has been subjected to saturation of the binding material, thus removing any excess coating from the surface of the sheet material in order that other forms of coating may be applied and effect binding engagement with the surface fibres.

The adhesive material withwhich the sheet is coated, may be formed from various ingredients having certain characteristics, as hereinafter pointed out, but one simple and inexpensive formula which has been devised comprises a mixture of glue, emollient polyhydric alcohol and invert sugars, which, upon drying, becomes nontacky, and forms a substantially smooth, hard surface upon both sides of the sheet, entirely covering the surface fibres. Any type of glue, which will remain non-tacky under normal atmospheric conditions, may be employed, but for the purpose of convenience and economy it is preferred to utilize glue which is soluble in water. The polyhydric alcohol in the mixture eliminates brittleness, which might cause the sheet to crack, and also present difficulties in cutting the sheet to form the stencil. The small portion of invert sugars used in the mixture adds to its binding properties, and also results in obtaining an exceedingly smooth surface to facilitate marking of the stencil design on the sheet. Also, the invert sugars and polyhydric alcohol add to the resistant qualities of the mixture, which is highly essential to prevent mutilation of the edges of the cut-out design, thus insuring sharp, clean outlines for the design etched or blasted in the work.

In use, it is merely necessary to sponge one surface of the material with water in order to render the adhesive coating sufliciently tacky to securely adhere the material to the glass or marble to be blasted; The material is then permitted to dry, after which the figure or design is drawn upon the sheet and then cut out with a knife or suitable tool, the cut out portion being then stripped from the Work.

As heretofore explained, when the sheet becomes dry, after being applied to the work, the coating or surface formed by the adhesive material becomes sufliciently hard and non-tacky, to resist the action of the sand or other blasting material, and also prevent its accumulation on the material.

Whenthe blasting is completed, water is again applied to the material, causing the adhesive to become suificiently tacky to permit the material to be stripped from the work, and due to the cheapness in cost, the sheet can then be discarded.

From the foregoing explanation, it will be appreciated that an exceedingly inexpensive and efficient sheet has been provided, which embodies all of the essential requirements of a stencil for the particular class of work described, and which is extremely easy to handle and work without the use of protective sheet such as now employed in connection with other stencil sheets.

No attempt has been made to define the relative thickness of the material employed, inasmuch as this can be varied in accordance with the class of work for which the sheet is to be used. For instance, in marble etching or blasting a relatively thick sheet would be employed whereas in glass an extremelythin sheet would be used.

-On the other hand, it is not essential that the material be produced in sheets of diiferent thickness, inasmuch as either one or a plurality of superimposed sheets may be employed, depending upon the character of the work.

Also, the ingredients comprising the adhesive mixture may be varied, as well as their proportions, and while it is not intended tolimit the proportion of the ingredient hereinbefore speci fied, it has been found that a highly desirable mixture is obtained by the use of four parts of glue, two parts of emollient polyhydric alcohol, and one part of invert sugars.

In addition to the foregoing, sheet material treated in the manner described has a broad field of utility, and it has been found that the same may be employed for limiting or confining the application of liquid-finishing material, such as paints and lacquers applied to automobile bodies, furniture, and other objects. Likewise, because of its adhesive qualities, materials of the foregoing character may be advantageously employed merely as an adhesive tape or strip for securing or attaching various objects, as for instance in securing material of ordinary paper to parts of an automobile body to prevent the lacquer spray from coming in contact with the same.

While it is not essential, it is also contemplated that suitable dusting material may be applied to the surface of the sheet materials, when put up in roll form, to eliminate any possibility of sticking that might occur under certain atmospheric conditions.

Therefore, while the invention has been described and claimed in connection with stencil sheet materials, it is to be understood that the same broadly inculdes the product itself, regardless of its application or use.

We claim:

1. A new sheet material comprising a sheet of non-sized paper, impregnated and covered with an adhesive material consisting of substantially four parts of glue, two parts of emollient polyhydric alcohol, and one part of invert sugars.

2. A composition of matter for stencil sheets and the like consisting of approximately four parts of glue, two parts of emollient polyhydric alcohol, and one part of sugar.

3. A substantially flexible tough wear-resistant single-thickness sheet having normally nontacky surfaces rendered adhesive by the application of moisture, said sheet comprising a sheet of absorbent material impregnated with an adhesive mixture consisting of glue and emollient polyhydric alcohol substantially in the proportions of two to one respectively and relatively small amount of sugar.

GEORGE WAGNER. GRACE P. KE'I'I'ER. 

